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Texas Invasive Species Institute

Texas Invasive Species Institute

Onionweed

Asphodelus tenuifolius

Class: Liliopsida
Order: Liliales
Family: Liliaceae
Duration and Habit: Perennial herb

Asphodelus tenuifolius

Photographer: USDA APHIS PPQ Archive Source: USDA APHIS PPQ

Description

Dark green in color and grows 12 to 30 inches tall and 15 inches wide. Numerous smooth, nearly cylindrical hollow leaves apparent. Similar in appearance to onion leaves but lacks the onion scent and taste. The leaves are much shorter than the flowering stem and emerge from the base. Produces one to several stiff upright flower stem(s) up to 2 1/2 feet tall and branched. About three-fourths of an inch across with six petal parts, each white to pink with a brown or reddish stripe along the center. Flowers alternate along the branches. Fruit is spherical in shape; divided into three segments. Seeds are brown or black triangular, one-eighth inch long, wrinkled, pitted and three or six per fruit. Thickened root crowns with many fibrous roots and no developed bulb.

Ecological Threat

In pastures and rangeland, onionweed develops populations that exclude grasses and desirable forage species. This federally regulated weed poses a serious environmental and agricultural threat.

Biology

It seeds prolifically and can establish large populations quickly. Onionweed is found in roadsides, pastures, waste places, disturbed areas, grasslands, and suburban settings. It is drought resistant and prefers sandy or gravelly soils

History

Introduced as an ornamental. The spread of onionweed is mainly through the dispersal of its seeds on vehicles, machinery, animals, and water in open channels.

Native Origin

 Mediterranean region and from western Asia to northern India

Current Location

CA, NM and TX

Resembles

  Onionweed might be confused with some native onions (Allium spp.)

Management

Can be managed through cultivation. Does not infest regularly worked fields.

USE PESTICIDES WISELY: Can be managed through cultivation. Does not infest regularly worked fields.

References

Contributions from Texas Invasives for this species page are greatly appreciated.

United States Department of Agriculture. Animal and Plant Health Inspection Service. Program Aid No. 2010, Issued April 2009. 

Arizona Sonora Desert Museum. Onionweed (Asphodelus fistulosus).

Internet sources

www.aphis.usda.gov/

http://plants.usda.gov/core/profile?symbol=ASFI2

http://pest.ceris.purdue.edu/pest.php?code=PCTAQBA

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